1. Field of the Invention
The invention relates to a vehicle control apparatus and a vehicle control method that set a predetermined target control amount that is used in running of a vehicle, and control at least the vehicle on the basis of the target control amount.
2. Description of the Related Art
As an apparatus of controlling vibrations of a vehicle, there is known a vehicle control apparatus which uses a physical quantity corresponding to at least one of the accelerator operation, the steering operation and the brake operation performed by a driver, as an input command, and control at least one of the engine and the brake corresponding to the input command (e.g., Japanese Patent Application Laid-Open Publication No. 2004-168148). In order to control vibrations of a vehicle, this vehicle control apparatus corrects the input command provided by the driver, by using a motion model concerning vibration that occurs due to an input command from a driver, that is, the up-down and/or torsional vibration caused by the road surface reaction force on the tires, the vibration of the vehicle body unsprung weight related to the suspension, and the vibration of the vehicle body sprung weight that the vehicle body itself receives.
The vehicle control apparatus, however, uses a single motion model in order to correct the input command provided by a driver. Therefore, in a vehicle capable of changes in its running characteristics in accordance with the taste of a driver or the like, it sometimes becomes impossible to obtain good vibration control of the vehicle despite using the aforementioned vehicle control apparatus. That is, if the damping characteristic of the vehicle is changed upon a driver's request as for example, there occur changes in specifications of the vehicle, such as the pitching resonance frequency and the like, leading to a failure of the vibration control. Besides the cases where vehicle characteristics are changed upon a driver's request, vehicle specifications can also change due to various other factors, such as changes in the running state of the vehicle and in the environments of vehicle run.